You see a body lying across the road and need to stop. If your vehicle was initially traveling at 100 km/h and skids to a stop on a 2.5% upgrade, taking 75 m to do so, what was the coefficient of friction on this surface?
d b = ( 100 ∗ ( 1000 3600 ) ) 2 − ( 0 ) 2 2 ∗ ( 9.8 ) ∗ ( f + 0.025 ) = 75 m {\displaystyle d_{b}={\frac {\left({100*\left({\frac {1000}{3600}}\right)}\right)^{2}-\left(0\right)^{2}}{2*\left({9.8}\right)*\left({f+0.025}\right)}}=75m\,\!}
( f + 0.025 ) = ( 27.78 ) 2 2 ∗ ( 9.8 ) ∗ 75 {\displaystyle \left({f+0.025}\right)={\frac {\left({27.78}\right)^{2}}{2*\left({9.8}\right)*75}}\,\!}
f = 0.50 {\displaystyle f=0.50\,\!}
